Valve mechanism for elastic fluid engines



mmh 19, 1940. s, L, Q KNOX 2,193,821

VALVE MECHANISM FOR ELASTIC FLUID ENGINES -Marh19,194o. 75.1.. G'. Noxl Y 2,193,821

VALVE MEGHANISM FOR ELASTIC FLUID ENGINES March 19, 1940. s, G, KNOX 2,193,821

VALVE MECHANISM FOR ELASTIC FLUID ENGINES Filed Septl 18,v 1937 4 Sheets-Sheet 3 March 19, 1940. s. L; G. KNox l 2,193,821

VALVE MECHANISM FOR ELASTIC FLUID ENGINES Filed Sept. 18, 1937 4 Sheets-Sheet 4 ferma Per ./pace Patented Mar. .19', 1940 vUNITED STATES VALVE RIEGHANISM FOR ELASTIC FLUID ENGINES Samuel Lippincott Gll'viswold Knox, Englewood,

Application september 1s, 1937, seriai No. 164,560

1d Claims.

This invention relates to'valve mechanisms for elastic fluid engines, andmore particularly to a combined throttling, simpling and reducing valve mechanism` for compound engines of the type adapted to be operatedahead, stop and reverse by the continuous movement oi a single operating lever.

In explanation-of my invention, devices known as simpling valves have been used heretofore .for changing compound engines to simple engines for the purpose of. obtaining increased torque, as under starting and heavy load conditions. However, the prior `simpling valves are generally of the character requiring 'a lever independent of the engine control for their actuation when the simpling operation is desired. The present invention contemplates a combined valve mechanism for actuation by the engine control lever, which operates in one of its functions tok obtain increased torque for starting and heavy load requirements, which a simpling attachment will give. With such mechanism actuab-le by the single lever by which the engine is normally operated as a compound engine, the necessity of providing an independent lever for the simpling operation is obviated. Thus by the'proposal of the vpresent invention the operator will actuate the lever for normal compound engine operation. If. the load is more than the engine, running as a N compound engine, will start, the operator simply pushes his lever further along its path of movement, and such continued movement causes the valve mechanism to effect simpling and increased torque is obtained.

In order to discourage the use of the simpling function of the valve mechanism, except at starting or under conditions of actual necessity, the invention further contemplates a valve mechanism which is designed to admit a throttled supply of steam to the high pressure cylinder, and to the receiver during simpling operation. In this connection it will be appreciated that if steam were admitted freely through the valve mechanism, the operator would be tempted to hold his lever in a position to eifect simpling action of the valve in an attempt to utilize the added power for the work being done. This manner of operation would be quite detrimental to l the eiciency of the engine and would make for a heavy draft on boiler capacity. By the present invention such a practice is deliberately discouraged by insuring slow-speed operation of the engine when running as a simple engine,fbecause of the throttled supply of steam to the high pressure cylinder and to the receiver. Thus-the (Cl. 121-5105) l operator will move his lever so as to restore normal compound engine operation as quickly as possible. Y

In order that thevalve mechanism of the present inventiony may Work in connection with the piston type reversing and distributing valve incorporated in the compound engine of my prior development Without requiring any special manipulation, the invention contemplates use in the valve assembly of throttling and simpling valves of the poppet type which are so related to the reversing and distributing valve that they always open in the same direction regardless of the direction that 'the reversing and distributing `valve is moved from its central or stop position.

Other objects will be in part obvious and in part hereinafter pointed out in connection with the following analysis of this invention wherein is illustrated an embodiment of. the invention L in detail.

In the drawings- Fig. 1 is a schematic side elevation of a com- -pound engine having associated therewith the valve mechanism of the present invention;

Fig. 1Ay is a partial top View of certain of the vmechanisrnshown in Fig. l;

, Fig. 2 is an enlarged sectional View of the lthrottling and. simpling valve of the mechanism illustrated in Fig. 1;

Fig. 3 is a part-sectional 'View similar to Fig. 2 illustrating in further detail the actuating means for the valve mechanism;

Fig. 4' is a partiall sectional view through a compound engine of the type herein contemplated, illustrating vin detail the valves controlling exhaust from thel high pressure cylinder.

- 'In the drawings, in which like reference characters .designate like parts throughout the several views, there is illustrated schematically w in Fig. 1 the cylinder block 5 of a compound engine, generally'of the character in which the high 'pressure cylinder is arranged intermediate the low pressure cylindersasindicated in Fig. 4, vsteam from the boiler being supplied to steam line l0 connected into the valve mechanism V to be described, the steam thereupon passing to a reversing and distributing valve within the engine block as schematically indicated at I5 (Figs. 3 and 4). The reversing and distributing valve, which Ais preferably of the character employed with the valve gear and system of steam distribution as .disclosed and claimed in my copend- 'ing application Serial'No. 250,623, iiled` January 12, 1939, is actuated. to positions so astocause u amount.

forward, stop and reverse movement of the engine through a link connection (not shown) with a pin i5 (Fig. l) adapted to be rocked in either direction past its central or stop position by the operating lever Il. Thus actuation of lever il in counter-clockwise direction past its mid or stop position causes movement of the distributing valve to a position causing rotation of the engine in one direction. Actuation of lever Vi' past its mid position in the reverse direction causes the distributing valve to effect rotation of the engine in the other direction. At its mid or stop position, the lever Il moves distributing valve I5 to a position cutting off admission of steam to the steam cylinders.

Associated with the cylinder block 5 is a casing 5 enclosing the power take-off parts of the engine such as the cross-heads, connecting rods, cra-ni; shaft, and the like. As these parts and constructions generally referred to above form no part of the present invention they will not be described in detail.

Considering now the mechanism of the present invention, reference character 28 (Figs. 2 and 3) is an angled fitting forming a. part of the valve casing or barrel, one leg of which is fastened to the cylinder block as at 2l, and the chamber D within the fitting providing a path of flow for steam to the distributing valve I5 and thence to the high pressure cylinder. The ttng 20 may be provided with an opening 22 adapted to be closed by a cap 23 secured to the tting as by bolts 24. 'Iransversely disposed with relation to the other leg of the fitting and journaled in the tting Wall and in the cap 23 is a rock shaft 25 carrying a crank 26, adjacent the end of which is carried a roller 2l. Arranged in the path of movement of the roller are the stems 30, 3| of the poppet valves 32, 33, respectively. Valve 32 is an auxiliary valve whose stern 33 operates in the longitudinally bored stem of the main valve 33. Valve 32 normally closes inclined ports 35 of the conicaily shaped main valve 33, the main valve normally closing communication between the steam chamber D of fitting 20 and a chamber 38 having a restricted diameter or .orifice portion 33 provided in a tubular casing part 48 welded or otherwise secured in axial relation to one leg of the tting 23. The casing part 40 has the steam inlet connection I0 secured thereto for supplying the chamber 38 with steam at boiler pressure. With the parts so far described it will be seen that as shaft 25 is rocked roller 21 first lifts the auxiliary poppet valve 32 a very small Then the roller 2'! comes against the spindle or stem 3| of the main poppet throttle valve 33, with continued movement of the roller 2l lifting valves 32 and 33. The purpose of the small valve 32 is to permit a partial admission of steam to the engine without the hand feeling too much resistance and thus tending to .open the valve jerkily. As valves 32 and 33 are lifted, steam passes from line I0 and chamber 38 to the chamber D of the fitting 28 and thence to the high pressure cylinder of the engine, through the distributing valve and cylinder operating valve.

Valves 32, 33 are normally seated by the action of a coil spring 45, one end of which engages against a spring seat 46 rockably seating against valve 32, the other end reacting against an end of a tubular casing member 4l which is arranged axially with reference to the casing part 40 and secured thereto as by bolts 48. These bolts extend through an end cap 5B and also serve to securebetween the end cap and the adjacent end of tting 4l the casing part 5i to be described, the bolts being threaded into the end iiange provided on the part The closed end of the casing part 41 is elongated to provide a hub 53 extending into the related end of the chamber 38, the hub receiving the stem 54 of a poppet valve 56 normally closing off communication between chamber 38 and chamber 5l formed Within the casing part 41 through communicating passages 58.

Valve 56 is subjected to the pressure of steam 'in chamber 38 and, opening away from this chamber, would be lifted by the steam pressure were it not held down by the pressure of a spring 60 engaging against the valve 55. Spring 58 is made sufficiently powerful to hold valve 5G closed against full boiler pressure. However, continued rotation of rock shaft 25 causes roller 21 to lift valves 32, 33 until spring seat 46 engages against stem 54 of valve 56, thus forcing valve 56 to open against the pressure of spring 68. Steam from line I is thereupon admitted to chamber 5l.

The casing part 5| is provided with ports 62 which connect the chamber 57 with a chamber 63 formed in the end cap 58. Part 5I is further provided with a chamber 64, communication between chambers 63 and 61.'. being established upon lifting of a valve G5 whose stem extends into and engages against the end of a floating spring cage 66 against which one end of spring 30 reacts. Valve E5, which will hereinafter be referred to as a simplng valve, thus controls communication between chambers 53 and 64, the latter communicating with the receiver space through a connection lil (see Fig. 4).

Upon steam being admitted to chamber 5i' due to lifting of valve 56, steam is also admitted to chamber 63 through 4ports 32 and causes the simplng valve to open against the action of spring 68, thus admitting steam to the receiver through chambers 53, 64 and connection` Steam pressure in the receiver now builds up to a predetermined value at which back pressure in the chamber 34, combined with the pressure of spring acting on the stem of valve 65 through the floating cage 5B, causes valve 65 to close. In the preferred arrangement the area of valve 65 vand the pressure of spring G0 are so proportioned that valve 65 will close at a predetermined point,

for example, one-half full boiler pressure, despite ,1

the full boiler lpressure on top of it. It is obvious, however, that if it is desired to admit steam at boiler pressure to the receiver the spring 65 could be omitted or left loose, or other arrangements provided to pass steam direct from line l0 or chamber 38 to the receiver.

Connection 'I0 to the receiver is provided with a T ll, from which a line i2 extends to a small cylinder` l5 arranged in the exhaust space and placed generally under the middle of the high pressure cylinder. A check valve 74 is provided in line 1U between the receiver and the T Il to prevent steam from the receiver going to cylinder 'I5 during normal operation of the engine. Within the cylinder 'I5 is arranged a plunger 'I6 urged by an upwardly opening poppet valve 85 urged to closed Iposition by spring 86. I `Steam exhausting from the high pressure cylinder into the chamber 83 through the exhaust ports 8e, as occurs during normal compound engine operation, acts to overcome the forcev of spring 36, and thus lifts thev upwardly opening poppet valve 85, allowing steam to pass directly v'from the high pressure cylinder into the receiver high receiver pressure on top of it and will therefore remain closed while the exhaust from the high pressure cylinder passes directly lout .of the engine. The low pressure cylinders may simultaneously take the steam from the receiver and exhaust the engine as usual.

' By the above described arrangement it will be seen that lifting of valves 32, 33 in the manner described' first admits steam direct 'to the high pressure cylinder and only to the high pressure cylinder. When thisis done, the enginefacts as a normal compound engine. Further movement of the valves 32, 33 thereupon acts to throttle the flow .of steanrfrom ysteam line i3 to the chamber D and thence to the high pressure cylinder, due to the fact that the continued lifting of valves '32, 33 causes spring seat to move into the iestricted diameter portion 39` of the chamber 38. After this throttling 'takes place, the simpling valve 65 is opened, therebyxadmtting higher pressure steam from the 4boiler direct to the receiver space than the receiver would get in normal operation as a compound engine. 'Simultaneously therewith, ythrough steam being supplied through connection 12 to cylinder 'l5 to open valve 80, steam from the high pressure cylinder is allowed to 'exhaust directly from the engine instead ofl into the receiver space.

' The purpose of the choking or throttling action of the element 46 in its relatively raised position is to provide, when the flow of steam into the receiver space upon closing ofy the simpling valve is reduced for the reasons above explained, that the flow of steam into the high pressure cylinder direct from the boiler through valvesl 32, -33 will` also be throttled. Otherwise,

with the high pressure cylinder getting steam atfull boiler pressure, and with the valves 32 and-'33 Ain their full open position before any v throttling action is effected, the performance of the engine would be jerky, with the high pressure cylinder getting its maximum supply of lvboiler steam and exhausting directly to the atmosphere, while the low pressure cylinders would be getting the much reduced quantity coming from the simpling and reducing valve to the receiver space.

, While the steam pressure reducing action is as described above in the valvefmechanism illustrated, it is of course understood that other types of steam pressure reducing action maybe inlcorporated such as the well known types in which the steam pressure from the boiler is reduced Ionly when the boiler pressure exceeds the predetermined maximum pressure to be admitted to rgine in the other direction.

single operating lever by which the throttling the receiveigor in which a constant ratio s maintainedbetween the boilerpressure and the reduced pressure admitted to the receiver.

`Referring to Figs. 3 and 4, wherein is shown the valve mechanism operating means, it has been lpreviously pointed out that when the lever l1 is actuated in one direction the distributing valve l5v is moved to a position causing the engine to rotate in 'one direction and when moved in `the reverse direction actuates the distributing valve to a position causing rotation of the en- To permit of a and simplingvalves aforesaid may be actuated at or near the end of the forward and reverse strokes of the lever, whereby the operator may simply push his lever further along its path of rmovement to effect simpling action regardless of direction of rotation of the engine asa compound engine, there are provided the connections lated' rod sockets Sla and Sib. Threaded into the socket members so that their axes converge are the rods 92, 93. Rod 32 extends through a pivoted socket member 34 carried by the lever and arranged relatively above the axis of pin i3 on which lever turns. Rod 93 similarly extends througha pivoted socket member 95 carried by the lever relatively below the axis of thelever fulcrum pin I6. 'Ihe ends of each of l the rods S2, 93 are threaded and are each provided with a stop nut 96 with which may be associated a lock nut 37.

In operation, and assuming that lever l1 has been .actuated in either direction to take up the lostV motion provided to permit the reversing and distributing valve to be moved well-over into a definite forward or reverse position before steam gets past ,the valves 32, 33, further movement of lever l'l in that direction causes a stop 96 to engage either one of the sockets 94, 95 depending on the direction of throw of the lever, and shaft 25 is'rotated to lift valves 32, 33 and thus admit steam from line I3 to chamber D and' thence to the high pressure cylinder. The engine `now operatesl as a compound engine and continues to so operate up to the point Where valves 32, 33 engage the stem l54. Further movement of the lever Il in the direction to which it has been actuatedl changes the engine from com pound to simple, as valves 32, 33 lift stem 54 and open the ysimpling valve 65 as described.

AIt is to be here noted that axial movement of either rod 92, S3 results in turning movement ofcrank arm 96) and rocking movement of ,the rock shaft-25 always in the same direction. Uniform directional rocking movement of `the shaft Z5y thus results in opening movement of the poppet valves 32, 33 and `simpling valve 35 in the same direction, regardless of whether simpling is eiected near the end of either the forward or reverse operations of the engine.

In addition tothe rabove operation, which relates generally to conditions of unusual load,

then between its cut off position and the end of its stroke, or if it is at or near dead center, so that normal opening of the valve 33 does not start the engine, the lever I1 can be further actuated so as to cause the simpling valve to admit steam to the receiver which in turn is admitted to the low pressure cylinder or cylinders to actuate Whichever of the pistons thereof is in a position to start the engine. Thus direct admission of steam to the receiver upon the described operation of the lever l'l assures starting of the engine from all positions.

As many changes could be made in carrying out the above cons ructions, without departing from the scope oi the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

l. In a mechanism for simpling a compound engine incorporating a high pressure cylinder, a receiver space, at least one low pressure cylinder receiving steam from the receiver` space, and an exhaust space, the combination of a lever movable to a position in which it eiTects admission of steam to the engine for normal compound operation, during which operation the high pressure cylinder eidiausts into the receiver space, means responsive to actuation of the lever beyond that position to en t continued admission ol' steam to the high pressure cylinder, and also to effect admission oi steam direct to the receiver at a relatively higher' pressure than would result from normal compound operation, and exhaust control mechanism including means responsive to the relatively high receiver pressure to cause the high pressure cylinder to exhaust directly into the exhaust space.

2. In mechanism for throttling and simpling a compound engine incorporating a high pressure cylinder, a receiver space, at least one low pressure cylinder receiving steam from the receiver space, and an exhaust space, the combination of a lever :lovable to a position in which it ei'ects admission of steam to the engine for normal compound operation, during which operation the high pressure cylinder exhausts into the receiver space, means responsive to actuation of the lever beyond that position to eiect throttling of the steam being admitted to the high pressure cylinder, and also to efect admission of steam direct to the receiver a., a relatively higher pressure than would result from normal compound operation, and exhaust control mechanism including means responsive to the relatively high receiver pressure to cause the high pressure cylinder to exhaust directly into the exhaust space.

3. In mechanism for throttling and simpling a compound engine incorporating a high pressure cylinder, a receiver space, at least one low pressure cylinder receiving steam from the receiver space, and an exhaust space, the combination of a lever movable to a position in which it effects admission of steam to the engi e for normal compound ope -ation, during which operation the high pressure cylinder exhausts into the receiver space, a throttling and simpling valve mechanism responsive for actuation to the actuation or' the lever beyond that position rst to eiiect throttling of the steam being admitted to the high pressure cylinder and thereafter to admit steam direct to the receiver at a relatively higher pressure than would result from normal compound operation, and exhaust control mechanism including means responsive to the relatively high receiver pressure to cause the high pressure cylinder to exhaust directly into the exhaust space.

4. In `mechanism ior throttling and simpling a compound engine incorporating a high pressure cylinder, a receiver space, at least one low pressure cylinder receiving steam from the receiver space, and an exhaust space, the combination of a lever movable to a position in which it eiects admission oi steam to the engine for normal compound operation, during which operation the high pressure cylinder exhausts into the receiver space, means responsive to the actuation of the lever beyond that position iirst to effect throttling of the steam being admitted to the high pressure cylinder, means also responsive to the actuation oi the lever beyond the position aforesaid thereafter to eil'ect admission or' steam direct to the receiver at a relatively higher pressure than would result from normal compound operation, and exhaust control mechanism including means responsive to the relatively high receiver pressure to cause the high pressure cylinder to exhaust directly into the exhaust space.

5. In mechanism for throttling and simpling a reversing compound engine incorporating a high pressure cylinder, a receiver space, at least one low pressure cylinder receiving steam from the receiver space, and an exhaust space, the combination of a lever movable from a mid-position to forward and reverse positions in which it effects forward and reverse rotation of the engine operating as a compound engine, during which operation the high pressure cylinder exhausts into the receiver space, mechanism including unidirectionally operable throttling and simpling valves each responsive for actuation to the actuation of the lever beyond the forward and reverse positions aforesaid to eiect throttling of the steam being admitted to the high pressure cylinder and to admit steam direct to the receiver at a relatively higher pressure than would result from normal compound operation, and exhaust control mechanism including means responsive to the relatively high receiver pressure to cause said high pressure cylinder to exhaust directly into the exhaust space.

6. In mechanism for throttling and simpling a reversing compound engine incorporating a high pressure cylinder, a receiver space, at least one low pressure cylinder receiving steam from the receiver space, and an exhaust space, the combination of a lever movable from a midposition to forward and reverse positions in which it eiects forward and reverse rotation of the engine operating as a compound engine, during which operation the high pressure cylinder exhausts into the receiver space, means unidirectionally responsive to actuation of the lever beyond the forward and reverse positions aforesaid to effect throttling oi the steam being ad rnitted. to the high pressure cylinder and to eiect admission of steam direct to the receiver at a relatively higher pressure than would result from normal compound operation, and exhaust control mechanism including means responsive to the relatively high receiver pressure to cause the high pressure cylinder to exhaust directly into the exhaust space.

7. In mechansin for throttling and simpling a reversing cor "und engine incorporating a high pressur receiver space, at least one low pressure cylinder receiving steam from the receiver space, and an ezdiaust space, the

on will.

Vcombination o'f'va lever"movable from` afmid-f position toforward and reverse positions in which it effectsl forward and reverse rotation of lthe engine' operating as a compound engine, during which operation the high pressurecylinder ex haustsinto' the receiver space, meansunidirectionally responsive to' `actuatior 1` l of,y the Ilever beyond'the forwardand reverse positions aforesaid to eiiectfthrottling of the steam being admittedto thejhigh pressure cylinder', means also unidirectionally yresponsive to actuation of the lever beyond the forward and reverse' positions aforesaid to effect admission of steam direct to the receiver at a higher pressure than Would result from normal compound operation, and exhaust control mechanism including means'r responsive to the relatively high receiver pressure to'cause the high pressure cylinder to exhaust dir ectlyinto the exhaust space.

8, In apparatus of the character described," the combination of a steam engine incorporating a high pressure cylinder, a receiver space, the high pressure cylinder normally exhausting into the receiver space, at least one low pressure cylinder receiving its steam from the receiver space, and an exhaust space, a steam line to the engine, valve means in said line for controlling admission of steam to the high pressure cylinder, valve means in said line for controlling admission of steam direct to the receiver, mechanism responsive to the receiver pressure following actuation of the second valve means and including means responsive to the relatively high receiver pressure to cause the high pressure cylinder to exhaust directly to the exhaust space, and means for actuating both said valvemeans.

9. In apparatus of the character described, the combination of a steam engine incorporating a high pressure cylinder, areceiver space, the high pressure cylinder normally exhausting into the receiver space, at least one low pressure cylinder receiving its steam from the receiver space, and an exhaust space, a steam line to the engine, valve means in said line for controlling admission of steamA to the high pressure cylinder, valve means in the line actuable upon a predetermined actuation of the first valve means for controlling admission of steam direct to the receiver, and mechanism responsive to the actuation of the second valve means and including means responsive to the relatively high receiver pressure to cause' the high pressure cylinder to exhaust directly into the exhaust space, and means for actuating the first valve means.

l0. In apparatus ofthe character described, the combination of a steam engine incorporating a high pressure cylinder, a receiver space, the high pressure cylinder normally exhausting into the receiver space, at least Aone low pressure cylinder receiving its steamfrom the receiver space, and an exhaust space, a steam line to the engine, valve `means in said line for conu trolling admission. of steam to the high pressure cylinder, means for throttlng steam admitted to the high pressure cylinder under the control of the valve means, simpling valve means for controlling admission of steam direct from the line to the receiver, the throttling means and the simpling means being actuable upon a predetermined actuation of the rst valve means, mechanism responsive to the actuation of the second valve means and including means responsive to the relatively high receiver pressure to cause the high pressure cylinder to exhaust directly into tlieexhaust'space, and means for, actuating the the receiver space, at Ileast one low pressureA cylinder receiving its steam from the receiver space, and an exhaust space, a steam line to the engine, valve means in `said line for controlling admission of steam to the high pressure cylinder, means for throttling steam admitted to the high pressure cylinder under the control of the valve means, simpling valve means operative to admit steam direct from said line to the receiver at a pressure lower than the line pressure but higher than that resulting from normall compound operation, the throttling means and the simplingjmeans being actuable upon a predetermined actuation of the first valve means, mechanism responsive to the actuation of said simpling means and including means responsive to the relatively high receiver pressure to cause the high pressure cylinder to exhaust directly into the exhaust space, and means for actuating the first valve means.

12. In apparatus of the character described, the combination of a steam engine incorporating a high pressure cylinder, a receiver space, the high pressure cylinder normally exhausting into the receiver space, at least one low pressure cylinder receiving its steam from the receiver space, and an exhaust space, a steam line to the engine, a puppet-type control valve in said line for controlling admission of steam to the high pressure cylinder, spring means normally closing said valve, means for lifting said valve, a simpling valve operatively connected in the line and controlling the passage of steam from the line direct to the receiver, said simpling valve being responsive for its actuation to the pressure of steam from the line, means operative upon a predetermined lifting of the control valve to admit steam to the simpling valve and thence at relatively high pressure to the receiver, and mechanism responsive to actuation of the sim pling valve and including means `responsive to `the relatively high receiver pressure to cause the high pressure cylinder to' exhaust directly into the exhaust space.

13. In apparatus of the character described, the combination of a steam engine incorporating a high pressure cylinder, a receiver space, the high pressure cylinder normally exhausting into the receiver space, at least one low pressure I cylinder receiving its steam from the receiver space, and an exhaust space, a steam line to the engine, a poppet-type control valve in said line for controlling admission of steam to the high pressure cylinder, spring means normally closing said valve, means for lifting said valve,

. a simpling valve operatively connected in the line and controlling the passage of steam from the line direct to the receiver, spring means normally maintaining the simpling valve in one position, and the simpling valve moving against said spring means in response to the pressure of steam from the line, a poppet-type valve controlling admission of steam from the line to the simpling valve, spring means normally closing the last-named valve, and the last-named valve lifting upon a predetermined lifting of thefcontrol valve whereby to admit steam to the simpling valve and thence at relatively high LIU pressure to the receiver, and mechanism responsive to actuation of the simplng valve and including means responsive to the relatively high receiver pressure to cause the high pressure cylinder to exhaust directly into the exhaust space.

14. In apparatus of the character described, the combination of a steam engine incorporating a high pressure cylinder, a receiver space, the high pressure cylinder normally exhausting into the receiver space, at least one low pressure cylinder receiving its steam from the receiver space, and an exhaust space, a steam line to the engine, a poppet-type control valve in said line for controlling admission of steam to the high pressure cylinder, spring means normally closing said valve, means for lifting said valve, a simpling valve operatively connected in the line and controlling the passage of steam from the line direct to the receiver, spring means normally maintaining the simpling valve .in one position, and the simpling valve moving against said spring means in response to the pressure of steam from the line, means operative upon a predetermined lifting of the control valve t0 throttle the admission of steam to the high pressure cylinder, a poppet-type valve controlling admission of steam from the line to the simpling valve, spring means normally closing the lastnamed valve, and the last-named valve lifting upon a further predetermined lifting of the control valve whereby to admit steam to the sim-pling valve and thence at relatively high pressure to the receiver, and mechanism responsive to actuation of the simplng valve and including means responsive to the relatively high receiver pressure to cause the high pressure cylinder to exhaust directly into the exhaust space.

ySAMUEL LIPPINCOTT GRISWOLD KNOX. zo 

